Inductor and converter having the same

ABSTRACT

The present disclosure discloses an inductor and a converter having the same. The inductor includes a magnetic core and a winding, the winding is provided within a window of the magnetic core, the winding includes a main body part and a sampling part, the main body part and the sampling part are connected in series, and a length ratio of the sampling part to the main body part is less than 2; wherein the main body part is formed of a low resistivity conductive material, the sampling part is formed of a low temperature coefficient conductive material, and a current flowing through the inductor is sampled across two ends of the sampling part. The inductor can obtain a current detection signal with high accuracy and low temperature drift with a compact structure, without increasing detection loss.

CROSS REFERENCE TO RELATED APPLICATIONS

The present application is a divisional application of U.S. applicationSer. No. 14/688,669, filed on Apr. 16, 2015, and claims priority under35 U.S.C. § 119 to the U.S. application Ser. No. 14/688,669, filed onApr. 16, 2015, Chinese Patent Applications No. 201410201425.9, filed onMay 13, 2014, and Chinese Patent Applications No. 201410310324.5, filedon Jul. 1, 2014, the entire contents of which are incorporated herein byreference.

TECHNICAL FIELD

The present disclosure relates to an inductor and a converter, and moreparticularly, to an inductor integrated with a thermal-stable samplingpart and a converter having the inductor.

BACKGROUND

In a converter system, current detection is very important for realizingcurrent mode control, current sharing, current monitoring, currentoverload limiting and current overload protection. The existing currentdetection method performs detecting/sampling to an output current byusing a current detection resistor with high accuracy, by using a directcurrent (DC) resistance of an output conductor, or by using anon-resistance of switch, etc.

FIG. 1 is an existing current detection circuit using the currentdetection resistor with high accuracy. As shown in FIG. 1, the currentdetection resistor includes a sampling resistance Rsense and adifferential amplifier OPA. An output inductor Lo has an inductance Land an equivalent series resistance DCR. The output inductor Lo isconnected to the sampling resistance Rsense in series. Input terminalsof the differential amplifier OPA are connected to the samplingresistance Rsense in parallel for amplifying a voltage signal across thesampling resistance Rsense so as to obtain a current detection signal.The magnitude of the current signal flowing through the samplingresistance Rsense may be known by measuring voltages across the samplingresistance Rsense and via I=V/R. It should be noted, the samplingresistance Rsense is a current detection resistor with high accuracy.

The method for detecting current by using a current detection resistorwith high accuracy has the advantage of high current detection accuracyand low temperature drift. Since a resistance with a low temperaturecoefficient may be adopted, the influence by the temperature drift canbe avoided. However, this method has the following deficiency: when thecurrent flowing through the current detection resistor is relativelylarge, a relatively large loss may be occurred in the current detectionresistor, thereby heat dissipation issues need to be considered duringthe design of circuit. In addition, the current detection resistor withhigh accuracy occupies a relatively large space.

FIG. 2 is an existing current detection circuit using the on-resistanceof switch, which can efficiently save space and have a relatively lowconduction loss. However, this solution has relatively low currentdetection accuracy and relatively large temperature drift.

FIG. 3 is an existing current detection circuit using a parasiticresistance of the output inductor. As shown in FIG. 3, the currentdetection circuit includes an output inductor Lo, a resistance R, acapacitance C and a differential amplifier OPA, wherein the outputinductor Lo includes an inductance L and an equivalent series resistanceDCR. The resistance R and the capacitance C constitute a RC filteringcircuit for filtering sampling signals of the output inductor Lo.

When L/R_(DCR)=RC is satisfied, a voltage on the capacitance is inproportion to a current i_(L) flowing through the inductance L. Thereby,the magnitude of the load current and inductive current may be detectedonly by detecting the magnitude of the voltage on the capacitance. Suchmethod is convenient and simple, can save space efficiently, and has arelatively low conduction loss, but has relatively low current detectionaccuracy and relatively large temperature drift.

Therefore, a new current detection solution is needed.

The information described above is only used to enhance theunderstanding of the background of the present disclosure, and thus mayinclude the information which is not regarded as the ordinary skill inthe art for the person skilled in the art.

SUMMARY

One object of the present disclosure is to provide a novel inductor forcurrent detection. The inductor can generate a current detection signalwith high accuracy and low temperature drift, occupy small space, andhas a low conduction loss. Another object of the present disclosure isto provide a converter adopting the above-mentioned novel inductor.

Other objects, features and benefits of the present disclosure maybecome apparent by the following detailed description, or partiallyunderstood by practicing the present disclosure.

According to a first aspect of the present disclosure, there is providedan inductor having a current sampling function, including: a magneticcore including at least one window; and at least one winding providedwithin the at least one window, wherein the at least one windingincludes a main body part and a sampling part, the main body part has afirst end and a second end, the sampling part has a first end and asecond end, the first end of the sampling part is connected to thesecond end of the main body part such that the main body part and thesampling part are connected in series, and a length ratio of thesampling part to the main body part is less than 2; wherein the mainbody part is formed of a low resistivity conductive material, thesampling part is formed of a low temperature coefficient conductivematerial, and a current flowing through the inductor is sampled acrosstwo ends of the sampling part.

According to a second aspect of the present disclosure, there isprovided a converter, including the inductor mentioned above, theconverter being configured to obtain a current detection signal of theconverter by the sampling part of the inductor.

According to another aspect of the present disclosure, there is providedan inductor, including: a winding including a main body part and asampling part which are connected in series, a length ratio of thesampling part to the main body part is less than 2; and a first andsecond sampling terminals for detecting voltages across two ends of thesampling part, wherein the main body part is formed of a low resistivityconductive material, and the sampling part is formed of a lowtemperature coefficient conductive material.

According to a third aspect of the present disclosure, there is provideda converter, including the inductor mentioned above, the converter beingconfigured to obtain a current detection signal of the converter by thefirst and second sampling terminals of the inductor.

According to the technical solutions in the present disclosure, theinductor may obtain the current detection signal with high accuracy andlow temperature drift with a compact structure, without increasingdetection loss.

BRIEF DESCRIPTION OF THE DRAWINGS

The above and other features and advantages of the present disclosurewill become more apparent by describing the embodiments thereof indetail with reference to the drawings.

FIG. 1 is a schematic diagram of a current detection circuit using acurrent detection resistor with high accuracy in related art.

FIG. 2 is a schematic diagram of a current detection circuit using anon-resistance of a switch in related art.

FIG. 3 is a schematic diagram of a current detection circuit using aparasitic resistance of an output inductor in related art.

FIG. 4 is a schematic diagram of an inductor winding according to oneembodiment of the present disclosure.

FIG. 5 is a schematic diagram of an inductor according to one embodimentof the present disclosure, and the inductor includes a magnetic core anda winding shown in FIG. 4.

FIG. 6 is a schematic diagram of a current detection circuit having theinductor shown in FIG. 5 according to one embodiment of the presentdisclosure.

FIGS. 7A, 7B and 7C are schematic diagrams of inductor windingsaccording to another embodiment of the present disclosure.

FIGS. 8A, 8B, 8C and 8D are schematic diagrams of inductor windingsaccording to another embodiment of the present disclosure.

FIG. 9 is a schematic diagram of an inductor winding according toanother embodiment of the present disclosure.

FIG. 10 is a schematic diagram of an inductor according to anotherembodiment of the present disclosure, and the inductor includes amagnetic core and a winding shown in FIG. 9.

FIG. 11 is a schematic diagram of a current detection circuit having theinductor shown in FIG. 10 according to one embodiment of the presentdisclosure.

FIG. 12 is a schematic diagram of a multiphase inductor according to oneembodiment of the present disclosure.

FIG. 13 is a schematic circuit diagram of having the inductor shown inFIG. 12 to the multiphase converter.

FIG. 14 is a schematic circuit diagram of an isolated DC-DC converteraccording to one embodiment of the present disclosure.

FIG. 15 is a schematic circuit diagram of an isolated full bridge DC-DCconverter according to one embodiment of the present disclosure.

FIG. 16 is a schematic block diagram of a converter having the inductorof the present disclosure according to one embodiment of the presentdisclosure.

FIGS. 17A and 17B are schematic diagrams of an inductor according toanother embodiment of the present disclosure.

FIGS. 18A and 18B are schematic diagrams of an inductor according toanother embodiment of the present disclosure.

DETAILED DESCRIPTION

Now the embodiments will be described more completely with reference tothe drawings. However, the embodiments can be implemented in variousforms, and shall not be interpreted to be limited to the embodimentsexplained herein. On the contrary, these embodiments are provided formaking the present disclosure to be complete and intact, and fordelivering the concept of the embodiments to the person skilled in theart completely. In the drawings, for clarity, thicknesses of areas andlayers are exaggerated. In the drawings, the same reference signsindicate the same or similar parts, and thus the repeated depiction ofthem could be omitted.

In addition, the described features, structures or characters may becombined in one or more embodiments in any appropriate manner. In thefollowing depiction, many specific details are provided for sufficientunderstanding of the embodiments of the present disclosure. However, theperson skilled in the art could appreciate that the technical solutionsof the present disclosure could be practiced without one or moreelements in the specific details, or by adopting other methods,components, materials and the like. In other conditions, the knownstructures, materials or operations are not illustrated or described indetail for avoiding blurring respective aspects of the presentdisclosure.

The typical embodiments embodying the features and advantages of thepresent disclosure will be described in detail in the followingdescription. It should be appreciate that the present disclosure mayhave various changes to different embodiments, all of which do notdepart from the scope of the present disclosure, and the description anddrawings are used for explanation in essence, but not for limiting thepresent disclosure.

FIG. 4 is a schematic diagram of an inductor winding according to oneembodiment of the present disclosure. FIG. 5 is a schematic diagram ofan inductor according to one embodiment of the present disclosure, andthe inductor includes a magnetic core and a winding shown in FIG. 4.FIG. 6 is a principle scheme of a current detection circuit having theinductor shown in FIG. 5 according to one embodiment of the presentdisclosure.

As shown in FIGS. 4 and 5, the inductor 1 according to the embodiment ofthe present disclosure includes a magnetic core 11 and a winding 12.However, the present disclosure is not limited thereto.

The magnetic core 11 has a first surface 111, a second surface (notshown) opposite to the first surface 111, and a window 13, and thewindow 13 runs through the magnetic core 11. The winding 12 is providedin the window 13.

As shown in FIG. 4, the winding 12 may include a main body part 121 anda sampling part 122 which are connected in series. For example, the mainbody part 121 has a first end 121A and a second end 121B, the samplingpart 122 has a first end 122A and a second end 122B, and the first end122A of the sampling part 122 is connected with the second end 121B ofthe main body part 121.

The main body part 121 is formed of a low resistivity conductivematerial. The sampling part 122 is formed of a low temperaturecoefficient conductive material. The length ratio of the sampling part122 to the main body part 121 is less than 2. According to anotherembodiment, the length ratio is less than 1.

In the present disclosure, the low temperature coefficient conductivematerial may be a conductive material having a temperature coefficientof less than 500 ppm, and the low resistivity conductive material may bea conductive material having a resistivity of lower than 0.1 Ω·mm²/m. Inan embodiment, the low temperature coefficient conductive material maybe a conductive material having a temperature coefficient of less than300 ppm.

The temperature drift performance of the low temperature coefficientconductive material is superior to the low resistivity conductivematerial, while the resistivity of the low temperature coefficientconductive material is much larger than that of the low resistivityconductive material. According to the present disclosure, only part ofthe winding is replaced by the low temperature coefficient conductivematerial, and the low temperature coefficient conductive material shouldbe as short as possible for reducing the winding loss. The length of thelow temperature coefficient conductive material is just maintained toensure the winding to process and sense the current detection signal.The low temperature coefficient conductive material and the lowresistivity conductive material may be welded together via laserwelding.

According to an embodiment, the low temperature coefficient conductivematerial may be MnCu alloy or MnCuSn alloy, while the low resistivityconductive material may be copper. Compared with the copper, such alloyhas the features of low temperature drift coefficient and highresistivity. It can be seen from Table 1 below, even for the bestmaterial MnCuSn, although the temperature coefficient thereof is 10 ppm,the resistivity is about 16 times of pure copper. If the entire windingis replaced by the low temperature coefficient alloy, the DC resistanceof the winding will increase at least 16 times, which is unacceptable.

TABLE 1 Resistivity Material (Ω · mm²/m) Temperature Coefficient PureCopper 0.01751 0.00393 BMn40-1.5 (constantan) 0.48 0.00002 BMn3-12(manganin) 0.435 0.00003 MnCuSn 0.29 0.00001

In addition to a first inductive terminal 18 and a second inductiveterminal 20, the inductor 1 or winding 12 may also have a first samplingterminal (CS+)14 and a second sampling terminal (CS−)16 for detecting avoltage across the two ends of the sampling part. As shown in FIG. 4,the first end 121A of the main body part 121 functions as the firstinductive terminal 18, and the second inductive terminal 20 is connectedto the second end 122B of the sampling part. The first sampling terminal14 is connected to the second end 121B of the main body part 121, andthe second sampling terminal 16 is connected to the second end 122B ofthe sampling part 122. In this embodiment, the second sampling terminal16 and the second inductive terminal 20 are common terminal, but thepresent disclosure is not limited thereto. For example, the secondsampling terminal 16 and the second inductive terminal 20 may also beterminals separated from each other, as shown in FIGS. 8A-8D. Thesampling terminal and the inductive terminal being separated may reducean influence of a power current flowing through the inductor on thesampling current, thereby further improve the accuracy of the currentsampling. Moreover, the present disclosure may not include the secondsampling terminal, as the embodiment shown in FIGS. 7A-7B, a currentflowing through the inductor may be sampled directly by the firstsampling terminal 14 and the second end 122B of the sampling part 122,meanwhile, the first end 121A of the main body part 121 may function asthe first inductive terminal of the inductor, and the second end 122B ofthe sampling part 122 may function as the second inductive terminal ofthe inductor.

As shown in FIG. 4, the first sampling terminal 14 may include: a firstpart 141 which is connected to the main body part 121 and is formed ofthe same low temperature coefficient conductive material as the samplingpart 122; and a second part 142 which is located at an end of the firstpart 141 and is formed of a low resistivity conductive material, but thepresent disclosure is not limited thereto. For example, the firstsampling terminal may be formed of, for instance, the same lowtemperature coefficient conductive material as the sampling part 122, asshown in FIGS. 7A and 8B. Alternatively, the first sampling terminal maybe formed of, for instance, the same low resistivity conductive materialas the main body part 121, as shown in FIGS. 7B-7C and FIGS. 8C-8D.

The second sampling terminal 16 (the second inductive terminal 20) maybe formed of the same low resistivity conductive material as the mainbody part 121, but the present disclosure is not limited thereto. Forexample, the second sampling terminal may be formed of, for instance,the same low temperature coefficient conductive material as the samplingpart 122, as shown in FIGS. 8B-8C.

In addition, in order to ensure the high accuracy performance of thesampling current sampled across the two ends of the sampling part, acalibration notch 22 may be used to calibrate the resistance of thesampling part 122, but the present disclosure is not limited thereto.

In actual engineering applications, the second inductive terminal isformed of a low resistivity conductive material, which may reduce theprobability that the soldering tin creeps on the sampling part 122during welding, and thus further improve the accuracy of the currentsampling.

The first sampling terminal 14 and the second sampling terminal 16 maybe integrated together with the main body part 121 or the sampling part122, and may be welded by laser.

FIG. 6 is a principle scheme of a current detection circuit having theinductor shown in FIG. 5 according to one embodiment of the presentdisclosure. According to the present disclosure, the converter using theinductor shown in FIG. 5 to detect current may be an isolated ornon-insolated DC-DC converter, such as a buck converter, but the presentdisclosure is not limited thereto.

As shown in FIG. 6, the inductor according to the embodiment of thepresent disclosure may function as an output inductor Lo which convertsa pulse voltage into a DC voltage. The inductor Lo may be equivalent toan ideal inductor L and a DC resistance connected to the ideal inductorL in series. The DC resistance may be divided into two parts, i.e., a DCresistance DCR1 and a DC resistance DCR2. The DC resistance DCR1 is anequivalent resistance of the low resistivity copper material part in thewinding, i.e., mainly the main body part 121 in FIG. 4; and the DCresistance DCR2 is the low temperature coefficient part in the winding,i.e., the sampling part 122 in FIG. 4. The current flowing through theinductor Lo flows through the DC resistance DCR2 as the same time,thereby the current flowing through the inductor may be sampled bysampling the voltage across the two ends of the DC resistance DCR2, andthe voltage across the two ends of the DC resistance DCR2 is detectedand fed back to the high accuracy amplifier OPA. Since the DC resistanceDCR2 has the low temperature drift performance, the current detectionsignals outputted via the amplifier OPA may be regarded to be highaccuracy and low temperature drift, and provide the current signals withhigh accuracy to the circuit control.

As mentioned above, the windings shown in FIGS. 7A-7C and FIGS. 8A-8Dare similar to the winding shown in FIG. 4, which are not repeatedherein. It is apparent that the windings shown in FIGS. 7A-7C and FIGS.8A-8D may be applied to the inductor shown in FIG. 5.

In the solutions shown in FIG. 4, FIGS. 7A-7C and FIGS. 8A-8D, thesampling terminal is located at one side of the winding, i.e., islocated at one side of the magnetic core, but the present disclosure isnot limited thereto. For example, the sampling terminal may also belocated at two sides of the sampling part, i.e., two sides of themagnetic core.

FIG. 9 is a schematic diagram of an inductor winding according toanother embodiment of the present disclosure. FIG. 10 is a schematicdiagram of an inductor according to another embodiment of the presentdisclosure, the inductor including a magnetic core and a winding shownin FIG. 9.

As shown in FIG. 9, the winding 12 may include a main body part 121 anda sampling part 122 which are connected in series. The first end 122A ofthe sampling part 122 is connected to the second end 121B of the mainbody part 121. The main body part 121 and the first sampling terminal 14are separately connected to the first end 122A of the sampling part 122.The first end 121A of the main body part 121 functions as the firstinductive terminal 18. The second sampling terminal 16 and the secondinductive terminal 20 are separately positioned on the second end 122Bof the sampling part 122. The first sampling terminal 14 and the mainbody part 121 may be formed of a low resistivity conductive material.The sampling part 122 may be formed of a low temperature coefficientconductive material. The second sampling terminal 16 and the secondinductive terminal 20 may be formed of a low temperature coefficientconductive material or a low resistivity conductive material.

However, the present disclosure is not limited thereto. According toanother embodiment, the main body part 121 and the first samplingterminal 14 may be positioned at one end of the sampling part 122. Thesecond sampling terminal and the second inductive terminal sharing oneterminal are positioned at the other end of the sampling part. Thesecond sampling terminal and the second inductive terminal may be formedof at least one of the low temperature coefficient conductive materialand low resistivity conductive material, and the first sampling terminalmay be formed of at least one of the low temperature coefficientconductive material and low resistivity conductive material.

FIG. 11 is a principle scheme of a current detection circuit having theinductor shown in FIG. 10 according to one embodiment of the presentdisclosure. The current detection circuit shown in FIG. 11 has thesimilar structure and function with the current detection circuit inFIG. 6, and the same contents are not repeated herein. The differencebetween them lies in that the current detection circuit further includesa RC filter. Since two sampling terminal CS+ and CS− respectively areoutput from two sides of the window of the magnetic core, the detectedvoltage across the two ends of the pin includes a voltage across the twoends of the DC resistance DCR2 and a pulse volt-second balance voltageon the winding of the inductor. Adding a RC filter is used to filter thepulse volt-second balance voltage on the winding of the inductor,thereby a voltage across the two ends of the DC resistance DCR2 may beobtained. The voltage across the two ends of the DC resistance DCR2 isfed back to the high accuracy amplifier OPA. Since the DC resistanceDCR2 is a resistor with high accuracy and low temperature drift, theoutput from the amplifier OPA may be used as the current detectionsignal having high accuracy and low temperature drift.

FIG. 12 is a schematic diagram of a multiphase inductor according to oneembodiment of the present disclosure. The inductor according to theembodiments of the present disclosure may be a multiphase inductor. Asshown in FIG. 12, a two-phase inductor 2 includes a magnetic core 21having two windows 231 and 232. Two windings 221 and 222 respectivelyrun through the two windows 231 and 232 of the magnetic core 21 so as toform the two-phase inductor. The structure and function of the windings221 and 222 may be the same as those of the inductor shown in any one ofFIG. 4, FIGS. 7A-7C and FIGS. 8A-8D.

FIG. 13 is a schematic circuit diagram of having the inductor shown inFIG. 12 to the multiphase converter. The outputs of a plurality ofconverters may be connected in parallel, or connected interleavely, oreach converter provides a separate output. For each winding, the voltageacross the two ends of the low temperature coefficient part is detectedand fed back to the high accuracy amplifier OPA. Thereby, the currentdetection signal having high accuracy and low temperature drift may beobtained for each phase. The structure of the current detection circuitin the converter of each phase is similar to that shown in FIG. 6, whichis not repeated herein.

The inductor Lo in the embodiments of the present disclosure may beapplied to the isolated DC-DC converter shown in FIG. 14. The isolatedDC-DC converter shown in FIG. 14 may be an isolated full-bridge DC-DCconverter shown in FIG. 15. The secondary side of the isolatedfull-bridge DC-DC converter adopts a synchronous rectification. Thecircuit is known for the person skilled in the art, and thus is notrepeated herein.

FIG. 16 is a schematic circuit diagram of an application of theconverter according to one embodiment of the present disclosure, and thecircuit diagram thereof is shown in FIG. 13. As shown in FIG. 16, thecurrent signal detected by the inductor according to the embodiments ofthe present disclosure may be applied to various control functions, suchas current monitoring, current overload limiting, current overloadprotection and current sharing control.

The current monitoring circuit receives a current detection signal andsends the current detection signal to the system via analog pins ordigital pins.

The current overload limiting circuit receives a current detectionsignal, and if the current exceeds a threshold value, the currentoverload limiting circuit limits a duty cycle and limits an outputcurrent by limiting Vo.

The current overload protection circuit receives a current detectionsignal, and if the current exceeds a threshold value, the currentoverload protection circuit adjusts the duty cycle to be 0 so as toclose the output voltage Vo.

For example, the current sharing control circuit includes a currentsharing bus OPA (operation amplifier) and two current sharing OPAs. Thecurrent sharing bus OPA receives current of two phases so as to form acurrent sharing bus. Then, the current detection signals and the currentsharing bus signals of each phase are transmitted to the correspondingcurrent sharing OPA. The output voltage signals of the correspondingcurrent sharing OPA are transmitted to the corresponding output voltage(Vo) feedback OPA for adjusting the duty cycle to balance the current oftwo phases.

FIG. 17A illustrates a schematic diagram of an inductor according toanother embodiment of the present disclosure. FIG. 17B is a schematicdiagram of the inductor in FIG. 17A after removing the magnetic core 11.The inductor is a two-phase inductor, and hereinafter, one phase thereofis described. As shown in FIGS. 17A and 17B, the winding of the inductorincludes a winding printed in a printed circuit board (PCB). Forexample, the inductor includes a PCB winding board, the main body part121 is printed within the PCB winding board, and the current samplingpart 122, i.e., the low temperature coefficient part with high accuracyis provided on the PCB winding board. The current sampling part 122 may,for example, be connected to the main body part via welding, so as tofunction as one part of the winding of the inductor. In addition, theinductor is further added with a first sampling terminal CS+ and asecond sampling terminal CS− as pins of the current detection fordetecting a voltage across the two ends of the current sampling partwith high accuracy. Thereby, the current detection signal with highaccuracy and low temperature drift may be obtained. Additionally, pinsmay raise the inductance to form a float inductor.

FIG. 18A illustrates a schematic diagram of an inductor according toanother embodiment of the present disclosure. FIG. 18B is a schematicdiagram of the inductor in FIG. 18A after removing the magnetic core 11.As shown in FIGS. 18A and 18B, the inductor adopts a PCB winding. Onepin CS− of the PCB winding is replaced by a pin of low temperaturecoefficient conductive material, the pin of low temperature coefficientconductive material is used as the sampling part of the inductor, and afirst sampling terminal CS+ is added for detecting the voltage acrossthe two ends of the pin of low temperature coefficient conductivematerial. Thereby, the current detection signal with high accuracy andlow temperature drift may be obtained.

In one embodiment, the magnetic core 11 is a ferrite magnetic core, butthe present disclosure is not limited thereto. For example, the magneticcore 11 may also be formed of magnetic material having distributed gaps.

Here, a single-turn winding is explained as the embodiment of thepresent disclosure, but in actual applications, the winding 12 may be asingle-turn or a multiple-turn winding. FIG. 4 illustrates a single-turnwinding as an example. The winding may be a coil winding or a PCBwinding.

The inductor having a current sampling function provided by the presentdisclosure integrates the current sampling part into the winding of theinductor, thereby space may be saved, miniaturization of the converteris promoted, cost may be reduced and the current sampling loss may bereduced. The sampling part is formed of a low temperature coefficientconductive material, thereby reducing the influence of temperature onthe current sampling signals, increasing the current sampling accuracy,and providing a basis for precisely controlling the converter.

Although the present disclosure has been described in terms of theembodiments, it should be understood that such disclosure is not forpurpose of restriction. On the contrary, various changes andmodifications are apparent to those skilled in the art based on theabove disclosure. Accordingly, the present disclosure intends to coverall changes, modifications, and equivalent arrangements within thespirit and scope of the appending claims.

What is claimed is:
 1. A converter, comprising an inductor having acurrent sampling function, wherein the converter is configured to obtaina current detection signal of the converter by a sampling part of theinductor, and the inductor comprises: a magnetic core comprising atleast one window; and at least one winding provided within the at leastone window, wherein the at least one winding comprises a main body partand the sampling part, the main body part has a first end and a secondend, the sampling part has a first end and a second end, the first endof the sampling part is connected to the second end of the main bodypart such that the main body part and the sampling part are connected inseries, and a length ratio of the sampling part to the main body part isless than 2, wherein the main body part is formed of a low resistivityconductive material, the sampling part is formed of a low temperaturecoefficient conductive material, and a current flowing through theinductor is sampled across two ends of the sampling part, wherein theinductor further comprises a first sampling terminal and a secondsampling terminal, the first sampling terminal is connected to thesecond end of the main body part or the first end of the sampling part,the second sampling terminal is connected to the second end of thesampling part, and the current flowing through the inductor is sampledby the first sampling terminal and second sampling terminal, and whereinthe inductor further comprises a first inductive terminal provided atthe first end of the main body part, wherein the second samplingterminal also functions as a second inductive terminal, and the secondsampling terminal and the second inductive terminal are the sameterminal, have the same size and are commonly used.
 2. The converter asrecited in claim 1, wherein the first sampling terminal and secondsampling terminal are positioned at one side of the magnetic core. 3.The converter as recited in claim 1, wherein the first sampling terminaland second sampling terminal are positioned at two sides of the magneticcore.
 4. The converter as recited in claim 1, wherein a temperaturecoefficient of the low temperature coefficient conductive material isless than 500 ppm.
 5. The converter as recited in claim 4, wherein thetemperature coefficient of the low temperature coefficient conductivematerial is less than or equal to 300 ppm.
 6. The converter as recitedin claim 1, wherein a resistivity of the low resistivity conductivematerial is lower than 0.1 Ω·mm²/m.
 7. The converter as recited in claim1, wherein the main body part and the sampling part are welded togethervia laser welding.
 8. The converter as recited in claim 1, wherein thesampling part comprises a calibration notch.
 9. The converter as recitedin claim 1, wherein the inductor is a multiphase inductor.
 10. Theconverter as recited in claim 1, wherein the magnetic core is a ferritemagnetic core or a magnetic core having distributed gaps.
 11. Theconverter as recited in claim 1, further comprising a PCB winding board,wherein the main body part is printed within the PCB winding board, andthe sampling part is provided on the PCB winding board.
 12. Theconverter as recited in claim 1, further comprising a PCB winding boardand a plurality of pins, wherein the main body part is printed withinthe PCB winding board, and at least one of the pins is the sampling partof the winding.
 13. The converter as recited in claim 1, wherein thelength ratio of the sampling part to the main body part is less than 1.14. The converter as recited in claim 1, wherein the converter is anon-isolated DC-DC converter, or an isolated DC-DC converter.
 15. Theconverter as recited in claim 1, wherein the converter is a single-phaseDC-DC converter, or a multiple-phase DC-DC converter.
 16. The converteras recited in claim 1, wherein the current detection signal is used forcurrent monitoring, over-current limiting, over-current protection,current mode control, or current sharing.
 17. The converter as recitedin claim 1, wherein the inductor functions as an output inductor, andthe current detection signal is an output current detection signal.